During life, a variety of insults may limit the individual's ability to cope with future environmental challenges. As isolated events, such challenges may be manageable; but in combination and/or cumulatively they may be devastating. The intent of the proposed research is to: (1) examine the similarities of specific brain damage (septal lesions), malnutrition, and aging on behavior -- all three alter the ways an individual adapts to its environment; (2) explore how these challenges combine to affect an organism's behavioral coping abilities; and (3) investigate how specific environmental manipulations may either counteract or further aggravate the behavioral rigidity often induced by these three forms of insult. To such ends our specific research projects will continue to monitor: (1) consummatory adaptation patterns; (2) exploration and activity in novel and familiar settings; and (3) learning and performance of cognitive problems. While extrapolation of animal data to the human condition is always difficult, the utility of animal models is readily apparent. We believe that these experiments will contribute to a better quantitative and qualitative understanding of those variables which determine an organism's resiliency to environmental challenges. BIBLIOGRAPHIC REFERENCES: Donovick, P. J., Burright, R.G., Fuller, J.L., & Branson, P.R. Septal lesions and behavior: Effects of presurgical rearing and strain of mouse. Journal of Comparative and Physiological Psychology, 1975, 89, 859-867. Laughlin, M.E., Donovick, P. J., & Burright, R. G. Consummatory behavior in meadow voles (Microtus pennsylvanicus) and Mongolian gerbils (Meriones unguiculatus). Physiology & Behavior, 1975, 15, 185-189.